1. Field of the Invention
The present invention relates to the general art of static structures, and to the particular field of protecting openings through walls of static structures.
2. Discussion of the Related Art
Many people like to leave the doors of their homes open especially during mild weather. However, when a door is open, insects and debris often migrate through the open doorway and into the interior of the home. This is an unacceptable situation, especially in view of the many diseases that insects have been known to carry. Still further, even if a door is closed, if it is opened even briefly to allow someone to pass into or out of a building, that opening, no matter how brief, tends to permit insects and debris to migrate into the interior of the building. In some instances, due to temperature differences between the interior of the building and the exterior of the building, there actually is a pressure difference which tends to draw such unwanted items into the interior of the building. Thus, even if a building has a screen door or a storm door, opening that door may expose the interior of the building to invasion of insects or debris or other such unwanted elements.
Therefore, there is need for a system that will prevent movement of insects, debris or other such elements into the interior of a building through an open doorway. Still further, there is a need for such a system that will operate to protect the interior of a building even if a door is opened only very briefly.
While the art contains disclosures of air curtains used in association with loading dock doors and the like, these air curtains do not adequately prevent migration of insects and debris through an open doorway especially if that doorway is only very briefly opened, or only slightly opened.
It may be wasteful to operate an air curtain on a continuous basis; however, in a loading dock situation, such continuous operation may be acceptable since the access opening may be in nearly continuous use. However, such a situation usually does not exist for a homeowner.
Therefore, there is a need for a system that will prevent movement of insects, debris and the like through a doorway and is activated only when the doorway is open and is inactive at all other times.
However, to be fully effective, such a system should be activated as soon as the doorway is open enough for such unwanted elements to move through the doorway.
Therefore, there is a need for a system that will prevent movement of insects, debris and the like through a doorway and that will be active only when the door is open and will be inactive when the door is closed, but will be activated as soon as the door is open enough to permit unwanted elements to move through the doorway.
As is well known, if there is any possible path into a building, insects will find such a path. Therefore, in order to be fully effective, any system which is intended to prevent migration of insects, debris or the like into the interior of a building via an open door must protect essentially the entire doorway.
Therefore, there is a need for a system that will prevent the migration of insects, debris or the like into the interior of a building through an open door and which protects essentially the entire area of the doorway, from the bottom to the top and from one side of the doorway to the other side of the doorway.
It is a main object of the present invention to provide a system for preventing unwanted elements, such as insects, debris or the like, from moving into a building through an open door.
It is another object of the present invention to provide a system for forming a protective air layer across an access doorway of a building It is another object of the present invention to provide a system for preventing unwanted elements, such as insects, debris or the like, from moving into a building through an open door and which will be activated as soon as the door is opened and will be inactive at other times.
It is another object of the present invention to provide a system for preventing unwanted elements, such as insects, debris or the like, from moving into a building through an open door and which is oriented to provide a stream of air flowing in an outward direction with respect to the building interior.
It is another object of the present invention to provide a system for preventing unwanted elements, such as insects, debris or the like, from moving into a building through an open door and which is oriented to provide a stream of air flowing in an outward direction with respect to the building interior and in which the air flows at an oblique angle with respect to a plane containing the doorway.
It is another object of the present invention to provide a system for preventing unwanted elements, such as insects, debris or the like, from moving into a building through an open door and which is oriented to provide a stream of air flowing in an outward direction with respect to the building interior and which protects essentially the entire length dimension of the doorway.
These, and other, objects are achieved by a system for forming a protective air layer across an access doorway of a building comprising a wall of a building, the wall having an interior side inside the building and an exterior side and extending upwardly from a ground level; a doorway defined through the wall, said doorway having a length dimension and a width dimension, with the length dimension extending upwardly from the ground level, the doorway being contained in a plane; a jamb on the wall around the doorway; a door moveably mounted on the jamb to move between a closed position and an open position; a fan unit mounted on the jamb adjacent to the doorway, the fan unit including a motor unit mounted on the jamb adjacent to the doorway, two fan housings mounted on the jamb adjacent to the doorway and extending upwardly from the ground level, each fan housing including an intake side, a plurality of vents, each vent of the plurality of vents being oriented at an oblique angle with respect to the plane containing the doorway and directed away from the interior side of the wall, a rotor mounted inside each fan housing, and a plurality of arcuate rotor blades mounted on the rotor of each housing and oriented to draw air from the intake side of the housing associated therewith and move the air to the vents of the plurality of vents of the housing associated therewith; and a circuit which includes a switch mounted on the jamb to be held in an open position when the door is in the closed position and to move into a closed position when the door is moved into the open position, a power source electrically connected to the switch to be connected to the motor when the switch is in the closed position, the motor being activated and rotating the rotor blades when connected to the power source; the fan unit extending for essentially the entire length dimension of the doorway. Air flowing out of the vents of the plurality of vents moves at an oblique angle across the doorway with respect to the plane containing the doorway, with the plane containing the doorway being located between the air flowing out of the vents and the plane containing the doorway and between the exterior side of the wall and the interior side of the wall.
Thus, every time the door is opened, a curtain of air is set up across the doorway and is directed outwardly of the building. Any debris or insects will thus be blown outwardly with respect to the building each time the door is opened. This will protect the building against such unwanted intruders. Even if the door is only slightly cracked open, the curtain of air will be set up and the doorway will thus be protected. The air is directed at an oblique angle with respect to the plane containing the doorway and thus will blow outwardly with respect to the building thereby not only protecting the doorway but also tending to clean out the area adjacent to the doorway. Since the fan housings extend for the entire length dimension of the doorway, the air flowing out of the vents will cover the entire area of the doorway and thus will protect the entire area of the doorway.